82 



(ii) Pinnae of the sterile frond not 

 much broader than the others, 

 scarcely toothed. 



4. P. pellucida. 



(c) Bipinnatae. Lowest pinnae at least 

 bipinnatifid. 



(t) Pinnae cut down nearly to the rachis 

 into numerous linear oblong seg- 

 ments. 



5. P. quadriaurita. 



(if) Pinnae cut down into several narrow 

 linear lobes which widen sudden- 

 ly on both sides within a short 

 distance of the base. 



6. P. patens. 



(d) Tripartitae. Lowest pinnae much 

 longer than the others, often nearly equalling 

 the central portion of the frond. 



7. P. wallickiana. 



II. Stipes distant on a creeping rhizome, 

 indusium double. 



8. P. aquilina. 



